Trichoderma harzianum in vitro mycoparasitism on Peronospora belbahrii in basil (Ocimum basilicum)

Abstract

Mildew (Peronospora belbahrii) is the disease that, worldwide, causes the greatest loss in the production of basil (Ocimum basilicum). The objective of the present work was to describe the symptoms and identification the causal agents of the mildiu in basil, as well as the evaluation of the antagonism in vitro of Trichoderma harzianum-P. belbahrii. For this, samples of basil plants, cultivar Nufar, with natural infection by mildew were taken. P. belbahrii was isolated from basil plants and later antagonism tests were carried out in sterile PDA-based culture medium, in Petri dishes. The ability of T. harzianum to parasitize P. belbahrii in vitro, could be appreciated after 72 hours, when the antagonist conidium germinated, the hyphae directed their chemotrophic growth towards the conidiophores and mycelium of P. belbahrii. Subsequently, the Trichoderma hyphae began to coil, penetrate, vacuolate the conidiophores and mycelium of the pathogen.